(a) Field of the Invention
This invention relates to bicycle chain ring gears and the transfer of a bicycle chain from one gear to another and more particularly, but not by way of limitation, to a chain ring gear set where one or more of the ring gears is warped for a gradual and fluid lateral transfer of a bicycle chain from one chain ring gear to another chain ring gear in the ring gear set. The bicycle chain is moved using a chain derailer during the operation of the bicycle.
(b) Discussion of Prior Art
Heretofore, there have been a variety of different types of eccentric or elliptical shaped chain ring gears used in ring gear sets on a bicycle. In U.S. Pat. No. 4,218,931 to Tritenne, a bicycle crank unit is disclosed having a chain wheel that is eccentric with a crank spindle. The crank spindle carries an external toothed pinion to engage an internal gear carried on the chain wheel. In U.S. Pat. No. 4,201,120 to Segawa, a gear crank for bicycles is described. The crank includes a crank shaft, a pair of crank arms and a chain gear. The chain gear includes convex and concave portions.
None of the above mentioned prior art patents specifically disclose the unique features, structure and function of the subject chain ring gear set where one or more of the ring gears include warped portions for periodically reducing the distance between the perimeters of adjacent ring gears for ease in chain transfer from one to another and using a bicycle chain derailer.